Methods of formulating conductive wellbore fluids

Abstract

A method of formulating an oil-based wellbore fluid, the method comprising adding at least a plurality of conductive carbon black agglomerates or pellets having an average size of at least 500 μm to an oleaginous base fluid, and applying energy to the oil-based wellbore fluid to disperse the plurality of conductive carbon black agglomerates or pellets into the oleaginous base fluid as finer particles than the agglomerates or pellets.

What is claimed: 
     
       1. A method of formulating at least one oil-based wellbore fluid, the method comprising:
 providing conductive carbon black agglomerates comprising physically fused primary carbon black particles that form carbon black aggregates having branched and fibroid-like structures entangled to form the conductive carbon black agglomerates, wherein the carbon black aggregates have, when measured using Di-Butyl-Phthalate (DBP) absorption method, a pore volume of at least about 200 cm 3  DBP/100 g carbon black and up to about 500 cm 3  DBP/100 g carbon black, and further wherein conductive carbon black agglomerates have an average size of 500 μm to 5 mm; 
 adding the conductive carbon black agglomerates to an oleaginous base fluid to form an oil-based wellbore fluid; and 
 applying energy to the oil-based wellbore fluid by shearing or at least one dispersion method to disperse the conductive carbon black agglomerates into the oleaginous base fluid as finer particles than the conductive carbon black agglomerates. 
 
     
     
       2. The method of  claim 1 , further comprising: circulating the oil-based wellbore fluid in a subterranean well. 
     
     
       3. The method of  claim 2 , further comprising performing electrical resistivity measurements of the subterranean well. 
     
     
       4. The method of  claim 2 , wherein the conductive carbon black agglomerates are added to the oleaginous base fluid in an amount so as to permit electrical logging of the subterranean well. 
     
     
       5. The method of  claim 1 , wherein the oleaginous base fluid is selected from the group of diesel oil, a natural oil, a synthetically derived oil, a mineral oil, a silicone oil, or a combination thereof. 
     
     
       6. The method of  claim 1 , wherein the oil-based wellbore fluid has an electrical conductivity of at most 0.02 S/m when measured at 20 kHz. 
     
     
       7. The method of  claim 6 , further comprising: forming a filtercake with the oil-based wellbore fluid on at least a portion of a wall of a subterranean well, wherein the filtercake has an electrical conductivity of at least two orders of magnitude higher than the oil-based wellbore fluid. 
     
     
       8. The method of  claim 1 , wherein the at least one dispersion method comprises mixing, stirring, sonicating, or a combination thereof. 
     
     
       9. A method of formulating an oil-based wellbore fluid, the method comprising:
 providing an oleaginous base fluid; 
 providing conductive carbon black agglomerates comprising physically fused primary carbon black particles that form carbon black aggregates having branched and fibroid-like structures entangled to form the conductive carbon black agglomerates, wherein the primary carbon black particles have a volatile content below about 1% by weight, and further wherein conductive carbon black agglomerates have an average size of 500 μm to 5 mm; 
 adding the conductive carbon black agglomerates to the oleaginous based fluid to form an oil-based wellbore fluid; and 
 applying energy to the oil-based wellbore fluid by shearing or at least one dispersion method to disperse the conductive carbon black agglomerates into the oleaginous base fluid as finer particles than the conductive carbon black agglomerates. 
 
     
     
       10. The method of  claim 9 , further comprising: circulating the oil-based wellbore fluid in a subterranean well. 
     
     
       11. The method of  claim 10 , further comprising: performing electrical resistivity measurements of the subterranean well. 
     
     
       12. The method of  claim 9 , wherein the oleaginous base fluid is selected from the group of diesel oil, a natural oil, a synthetically derived oil, a mineral oil, a silicone oil, or a combination thereof. 
     
     
       13. The method of  claim 9 , wherein the conductive carbon black agglomerates are added to the oleaginous base fluid in an amount so as to permit electrical logging of a subterranean well. 
     
     
       14. The method of  claim 9 , wherein the oil-based wellbore fluid has an electrical conductivity of at most 0.02 S/m when measured at 20 kHz. 
     
     
       15. The method of  claim 14 , further comprising: forming a filtercake with the oil-based wellbore fluid on at least a portion of a wall of a subterranean well, wherein the filtercake has an electrical conductivity of at least two orders of magnitude higher than the oil-based wellbore fluid. 
     
     
       16. The method of  claim 9 , wherein the at least one dispersion method comprises mixing, stirring, sonicating, or a combination thereof. 
     
     
       17. The method of  claim 9 , wherein the volatile content of the primary carbon black particles is below about 0.7% by weight.